Jf. Benvenuti et al., DISPLACEMENTS OF THE TIBIAL TUBEROSITY - EFFECTS OF THE SURGICAL PARAMETERS, Clinical orthopaedics and related research, (343), 1997, pp. 224-234
A three-dimensional computer model is used, based on the finite elemen
t method, to investigate the effects of 1-, 1.5-, and 2-cm tibial tube
rcle elevations and of 0.5- and 1-cm medial displacements of the tuber
osity performed with different bone shingles. Patellar kinematics and
patellofemoral interface peak pressure, between 45 degrees and 135 deg
rees of passive knee flexion are compared for these different surgical
parameters with those of a normal knee not surgically treated. The sh
ingle lengths of 3, 5, 7, and 10 cm have little influence on the resul
ts. Augmenting tubercle medializations decrease the lateral peak press
ure but result in an overpressure of the medial facet that is 154% of
the normal peak value. With knee flexion between 45 degrees and 60 deg
rees, increasing tubercle elevations decreases lateral and medial peak
pressures, With flexion of more than 60 degrees, increasing elevation
s decrease the lateral peak pressure, but they augment and even cause
overpressure on the medial facet. An overpressure on the lateral facet
also is seen in midrange knee flexion (75 degrees-90 degrees) for all
tubercle elevation values. Increasing tubercle elevations and mediali
zations appear to be the predominant parameters from a biomechanical p
oint of view.